BIOS UPDATE issues. Screen is black or blank for hours after bios update (UEFI mode)

[Elvis2020]

Hello Community. please help me. 
I just updated my laptop bios to F.19 Rev.A version. 
and now the problem is that my laptop won't show anything on screen on boot up! 

i can't access my UEFI boot options. Pressing F2, F8, F10 or ESC on startup won't work anymore. the laptop keeps running but it won't show anything on screen. 

process i did. 

1. i installed BIOS in my flash drive. 
2. I pressed "Windows + B" to start automatic bios install mode. The bios setup did not ask me on which version of bios ID my laptop had. its "0836B". i had looked into the bios folder (from another laptop), it had 0836D, 0836B and other one.  
3. Bios was installed. 
4. Laptop restarted.
5. Now nothing is showing up on the screen! 

what could be the problem?
1. was the bios a corrupt file?
2. did i made any mistake on installing the bios file?

3. do i need to install anything before i had installed my bios?

please do help me fix this problem. 

problem actually started when i opened my laptop. i was trying to just blow the dust inside laptop and when i restarted my laptop, it suddenly shut down without any warning. later on during startup, thermal shutdown 90D was shown even when my laptop was really cool and there was no sign of heat. 
then i looked up in the hp support for solution. i found a post where i was meant to update the bios! and thats why I updated bios. 
it was pretty weird. before this bios update, my laptop used to shutdown when it came to loading up windows. 
but when i used to access bios, laptop would not shutdown. 
i even format my computer with windows 10, the laptop did not shut down! 
but after hp logo on screen and when laptop was trying to load up the windows, THEN THE LAPTOP SHUT DOWN. 

it clearly seems to be the software issue rather than hardware. 

please help! 

[The_Fossette]

@Elvis2020

I reviewed your post and I understand that the computer is not booting to Windows after updating the BIOS.

Don’t worry, I assure you I will try my best to get this sorted.

I recommend you roll back the BIOS to the previous version and check whether the issue is resolved.

Refer to the below article for detailed steps.

https://support.hp.com/in-en/document/c02693833

Let me know how it goes and you have a great day!

P.S: Welcome to the HP Support Community 😊

If you wish to show appreciation for my efforts, mark my post as Accept as Solution. Your feedback counts!

Cheers!

Stay Home – Stay Safe

[Elvis2020]

Thanks for the reply. 

1. i have already tried to do "Windows + B". Updated Bios and now my laptop is good as dead. it won't even allow me to access basic bios features with f1, f2 or f10 key. I had downloaded the bios for my laptop from the hp support center for my laptop model : HP Pavilion Power - 15-cb050od  with bios version 0836B  F.19 Rev.A
2. I tried "windows + V" to access CMOS. the laptop just shuts down to restart again. nothing shows up in screen. 
I opened up my laptop to look for the RTC battery. well I found that there was none! 

Beginning of the problem:

i had bought my laptop 3 months ago.  I wanted to add an additional 16GB RAM to my laptop. I opened my laptop myself thus voiding the warranty. I did some cleaning with the cooling fan and heat sink. I also changed the thermal liquid. Then i installed additional 16GB RAM.  Then i reassembled everything back and when i tried to open the laptop, my laptop shut down after showing the HP Logo (while trying to boot the windows)
after that i was never able to see the windows again. 
Everytime i tried to start the laptop, i was shown the. "Thermal Shutdown Occured 90D Temp" Error but my laptop was not even heated at all. 
i went to hp support website regarding the problem, and it had 1 solution listed. That was to update the BIOS! 
And then i updated my bios with the BIOS setup flash drive on "windows + B" mode because Firmware Management option is no more in the F2 section. 
My laptop showed the BIOS Installation window and installed the BIOS. 
The laptop then restarted and after that, it showed nothing. blank screen and now f1, f2, f10 does not show bios uefi window. 

i never had these problems with other laptops i have used in past. 
I am from Nepal. There are no spare BIOS Chips available here. I seem to have no choice but to change my motherboard, but its really costly. should i buy a new laptop or should i chose a new motherboard? 

my main question is. I opened my laptop and suddenly, it damaged/corrupted my BIOS. WHY? and HOW? I would be really grateful if i could get all possible scenario that could damage a BIOS chip when i opened the laptop. I only touched the heat sink, fan, changed thermal liquid and installed new 16GB DDR4 Ram. 

I would be really happy to know reasons behind this. waiting for your kind reply. 

Thank you. 

[KrazyToad]

@Elvis2020

Thanks for keeping us posted

Without having the computer in hand it's difficult to say why the BIOS failed and more importantly why you are unable to roll back the BIOS

At this point I suggest you contact HP Support in your Region for Service Options

1) Click on this link - www.hp.com/contacthp/ 
2) Select your product type below.
3) Enter the serial of your device. 
4) Select the country from the drop-down. 
5) Select the chat or get phone number options based on your preferences. 
6) Fill the web-form and proceed further.

Thank you